I too do not see shame as the major issue here, but rather imagination, the poetic faculty. The poet's long conceit is also the lover's idealizing bent. It catapults him into the heavens, separates him from the actual experience, the 'real' person before him, whose slipping away is also described metaphorically, as a quicksilver stream.

But the speaker's final regret is only half-hearted: he missed the chance to consummate an an act of physical love, but this is described rather flatly and abruptly at the end. On the other hand, on the strength of analogy, he's built an extraordinary castle in the air--the poem itself, perfectly gorgeous, satisfied and also satisfying. The official moral may be, 'Don't get lost in metaphor,' 'Seize the Day,' but the subtext is closer to that of Keats's "Ode on a Grecian Urn": The poem, perhaps unconsciously, suggests that the savory delight of prolonged expectation may be greater than the finite pleasure of consummation.

Morris D.